﻿/**
* Copyright (c) 2009 Sergiy Kovalchuk (serg472@gmail.com)
* 
* Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
* and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
*  
* Following code is based on Element.mask() implementation from ExtJS framework (http://extjs.com/)
*
*/
; (function ($) {

    /**
    * Displays loading mask over selected element(s). Accepts both single and multiple selectors.
    *
    * @param message Text message that will be displayed on top of the mask besides a spinner (optional). 
    * 				If not provided only mask will be displayed without a message or a spinner.  	
    * @param delay Delay in milliseconds before element is masked (optional). If unmask() is called 
    *              before the delay times out, no mask is displayed. This can be used to prevent unnecessary 
    *              mask display for quick processes.   	
    */
    $.fn.mask = function (message, delay) {
        message = message || '正在处理，请稍等……';

        $(this).each(function () {
            if (delay !== undefined && delay > 0) {
                var element = $(this);
                element.data("_mask_timeout", setTimeout(function () { $.maskElement(element, message) }, delay));
            } else {
                $.maskElement($(this), message);
            }
        });
    };

    /**
    * Removes mask from the element(s). Accepts both single and multiple selectors.
    */
    $.fn.unmask = function () {
        $(this).each(function () {
            $.unmaskElement($(this));
        });
    };

    /**
    * Checks if a single element is masked. Returns false if mask is delayed or not displayed. 
    */
    $.fn.isMasked = function () {
        return this.hasClass("masked");
    }; 

    $.maskElement = function (element, message) {
        //if this element has delayed mask scheduled then remove it and display the new one
        if (element.data("_mask_timeout") !== undefined) {
            clearTimeout(element.data("_mask_timeout"));
            element.removeData("_mask_timeout");
        }

        if (element.isMasked()) {
            $.unmaskElement(element);
        }

        if (element.css("position") == "static") {
            element.addClass("masked-relative");
        }

        element.addClass("masked");

        var maskDiv = $('<div class="loadmask"></div>');
        
        //auto height fix for IE
        if (navigator.userAgent.toLowerCase().indexOf("msie") > -1) {
            maskDiv.height(element.height() + parseInt(element.css("padding-top")) + parseInt(element.css("padding-bottom")));
            maskDiv.width(element.width() + parseInt(element.css("padding-left")) + parseInt(element.css("padding-right")));
        }

        //如果要遮罩的元素是body
        if(element.is('body')){
            width = Math.max(document.documentElement.clientWidth, document.body.clientWidth);
            height = Math.max(document.documentElement.clientHeight, document.body.clientHeight);
            
            maskDiv.width(width);
            maskDiv.height(height);
        }

        //fix for z-index bug with selects in IE6
        if (navigator.userAgent.toLowerCase().indexOf("msie 6") > -1) {
            element.find("select").addClass("masked-hidden");
        }

        element.append(maskDiv);

        if (message !== undefined) {
            var maskMsgDiv = $('<div class="loadmask-msg" style="display:none;"></div>');
            maskMsgDiv.append('<div>' + message + '</div>');
            element.append(maskMsgDiv);

            //calculate center position
            maskMsgDiv.css("top", Math.round(element.height() / 2 - (maskMsgDiv.height() - parseInt(maskMsgDiv.css("padding-top")) - parseInt(maskMsgDiv.css("padding-bottom"))) / 2) + "px");
            maskMsgDiv.css("left", Math.round(element.width() / 2 - (maskMsgDiv.width() - parseInt(maskMsgDiv.css("padding-left")) - parseInt(maskMsgDiv.css("padding-right"))) / 2) + "px");

            maskMsgDiv.show();
        }

    };

    $.unmaskElement = function (element) {
        //if this element has delayed mask scheduled then remove it
        if (element.data("_mask_timeout") !== undefined) {
            clearTimeout(element.data("_mask_timeout"));
            element.removeData("_mask_timeout");
        }

        element.find(".loadmask-msg,.loadmask").remove();
        element.removeClass("masked");
        element.removeClass("masked-relative");
        element.find("select").removeClass("masked-hidden");
    };

    $.fn.mask.defaults = {
        message:'正在处理，请稍等……',
        timeout:30000,
        delay: 0,
        opacity:0.4
    };

})(jQuery);
